3results about How to "Short filter time" patented technology

The invention discloses a crystal form A of acetyl L-carnitine hydrochloride, a preparation method of the crystal form A, and a bulk drug, a food additive, a feed additive and a composition containing the crystal form A. The crystal form A of the acetyl L-carnitine hydrochloride is good in solubility, high in stability, high in purity, regular in shape and suitable for being applied to bulk drugs, food additives and feed additives. The preparation method is simple in process, the crystal form A can be obtained at high yield through in-situ crystallization of a reaction solution and dispersion of ethanol, and the preparation method is suitable for large-scale industrial production.

This invention discloses a method for removing impurities from ferrous sulfate, a byproduct of titanium dioxide production, comprising the following steps: 1) taking ferrous sulfate and preparing a saturated solution; 2) adding dilute phosphoric acid, stirring thoroughly, and filtering to remove insoluble matter; 3) adding an appropriate amount of ammonia to the obtained solution, filtering, and evaporating the filtrate; 4) slowly stirring and cooling the remaining solution until the solution temperature drops to 10°C, centrifuging to obtain primary crystals and primary crystallization mother liquor; 5) dissolving the obtained primary crystals again and preparing a saturated solution, repeating steps 3) and 4) to obtain secondary crystals and secondary crystallization mother liquor; 6) dissolving the secondary crystals to prepare a ferrous sulfate solution, which can be directly used for the preparation of battery-grade iron phosphate. This method uses phosphoric acid, ammoniation, and recrystallization to remove impurities from ferrous sulfate through multiple processes. After impurity removal, the heptahydrate ferrous sulfate solid has high purity and low metal impurity content, and can be directly used for the synthesis of battery-grade iron phosphate after dissolution.

The application provides a digital filtering system for multi-domain analysis of a vector network analyzer, and the specific process of the digital filtering system for processing signals is as follows: multiple analog intermediate frequency input signals enter an analog-digital conversion control and holding unit through a signal conditioning circuit, so as to convert the multiple analog intermediate frequency signals into multiple digital intermediate frequency signals; the multiple digital intermediate frequency signals enter a multi-channel data synchronization unit; under a non-modulation measurement domain, the signals enter a continuous filtering unit, under a synchronous modulation domain, the signals enter a synchronous modulation filtering unit, and when in a data storage mode, a spectrum mode or other special modes, the signals enter an ADC data storage unit; a filtering coefficient generation and control unit generates different FIR filtering coefficients according to input data modes, and sends the filtering coefficients into a multi-channel parallel FIR filtering unit. The technical scheme of the application overcomes the problem that the filtering system in the prior art cannot meet the digital filtering requirements of the vector network analyzer under different measurement modes.